U.S. obesity rate levels off, but still an epidemic

Obesity among U.S. adults is continuing to level off after several decades of skyrocketing growth, new government data show.

In 2012, about 34.9% of the people in this country were obese, which is roughly 35 pounds over a healthy weight. That is not significantly different from the 35.7% who were obese in 2010.

In both 2010 and 2012 about 78 million adults were obese; more than 50 million of those were white, according to the latest statistics from the National Center for Health Statistics, part of the Centers for Disease Control and Prevention.

"Even though it looks like a slight drop in the percentage of adults who are obese, this difference is not statistically significant," says Cynthia Ogden, an epidemiologist with the National Center for Health Statistics. "This is more evidence that we're not seeing a change in adult obesity."

Harvey Grill, president of the Obesity Society, says, "The fact that we're at 35% of adult Americans who are obese is extremely troubling because their obesity will result in health problems for the majority of them."

Scott Kahan, director of the STOP Obesity Alliance at George Washington University, an obesity policy think tank, says, "The numbers are still at epidemic levels, and we need to continue to create smart strategies to address this health problem."

There has been no significant change in obesity rates since 2004 when the obesity rate was about 32%, Ogden says.

The prevalence of obesity increased dramatically in the 1980s and 1990s after being relatively stable in the USA between 1960 and 1980 when about 15% of people fell into the category.

The latest statistics did not include obesity rates for children and adolescents, but there has been some indication in the last CDC statistics on children that those rates have leveled off too.

This new analysis is based on data from the National Health and Nutrition Examination Survey, which is considered the gold standard for evaluating the obesity epidemic in the USA, because it is an extensive survey of people whose weight and height are actually measured rather than being self-reported.

Obesity is determined by calculating people's body mass index, a number that takes into account height and weight. Adults are considered obese if they have a body mass index (BMI) of 30 or greater. BMI measures body mass; it doesn't distinguish between fat and muscle.

A 5-foot-4 adult would be classified as obese if he or she weighed 174 pounds or more; a 5-foot-9 adult would fall into that category at 203 pounds or more.

Obesity takes a huge toll on people's health. It contributes to a long list of serious health problems including type 2 diabetes, cardiovascular disease, liver problems, degenerative joint disease, and some types of cancer.

Other new statistics:

• There was no significant change in obesity among men and women. In 2010, 35.8% of women were obese; in 2012, 36.1%. In 2010, 35.5% of men were obese; in 2012, 33.5%.

• The middle-age spread is still a problem. The prevalence of obesity is higher among middle-aged adults (39.5%) than younger (30.3%) or older (35.4%) adults.

"The percentage of obesity in Asians is quite low, but BMI is not a perfect measure of body fat," Ogden says. Studies have shown that Asians may have more body fat at lower BMI levels than whites so some countries, such as Taiwan, have adopted lower BMI cutoff points for overweight and obesity for Asians, she says.